How to get specific attribute in a json file using typescript?

Ionic Framework
1

i want to pass only the values from address attribute from json file to geocode parameter.

Get Data from Provider

this.serverservice.getData().subscribe(data =>{
      this.datasource.source = data.json();  
  });

JSON

 ([
      {
        "id": 1,
        "name": "Laura",
        "address": "philippines",
        "age": 47
      },
      {
        "id": 2,
        "name": "Walter",
        "address": "china",
        "age": 37
      }

Where I would like to pass the address attribute as a parameter of geocode function

geocode_func(geocoder, address){
       geocoder.geocode({address:this.datasource.source},(results,status) =>{this.rescall(results,status)} );
  }